G
eotextiles were one of the first textile products in human history. Excavations of
ancient Egyptian sites show the use of mats made of grass and linen. Geotextiles are ideal
materials for infrastructural works such as roads, harbors and many others. They have a bright
future, thanks to their multifunctional characteristics.
Geotextiles today are highly developed products that must comply with numerous standards. To
produce tailor-made industrial fabrics, appropriate machinery is needed. Germany-based Trützschler
Nonwovens Fleissner GmbH and Dilo Maschinensystem GmbH produce nonwovens machinery, and Lindauer
Dornier GmbH manufactures weaving machines. All three companies plus the Geosynthetic Materials
Association (GMA), United States, and the Association of the Nonwoven Fabrics Industry (INDA),
United States, provided useful information for this article.
Geotextile application areas
All illustrations: courtesy of Lindauer Dornier GmbH
Functions
Every textile product applied under the soil is a geotextile. The products are used for
reinforcement of streets, embankments, ponds, pipelines, and similar applications. Depending on the
required function, they are used in open-mesh versions, such as a woven or, rarely, warp-knitted
structure, or with a closed fabric surface, such as a nonwoven. The basic geotextile functions
include erosion control; protection; filtration; armoring; drainage; and separation, or barrier
function.
Geotextiles with their built-in functions are virtually tailor-made based on end-use or
application. Major requirements include: tensile strength; permeability to air, fluids and/or
light; mesh size suited to end-use, such as filtration, sieve or separation; chemical, mechanical
or thermal resistance; and durability.
Fibers
Most woven geotextiles are made of filament polyester (PET), polypropylene (PP), glass,
basalt, aramid or carbon fibers; with the fiber chosen based on the required functions, mainly
tensile strength and a very long product life. Typical end-use applications are roads, levees and
railroad embankments, among other applications. Nonwovens, usually made of PP and PET, are mainly
applied for barrier function end-uses such as filtration and separation. In addition, nonwovens
made of natural fibers, for example, are suitable for covering grass slopes. It is possible to
incorporate different kinds of seeds, such as grass, and the nonwoven cover will eventually
decompose as a green and natural surface grows on the construction.
Bast fibers, with their non-uniform fiber qualities, are beginning to be used in certain
nonwoven products. The same applies for recycled fibers. Currently, very few recycled fibers are
used. Also, recycled fibers do not always have the uniform properties required to form an even
product. When PET bottles are recycled in a way that produces uniform fibers, then recycled PET
fibers could be processed using needlepunch technology, Dilo mentions.
Coating materials play a very important role in enhancing geotextile properties and
functions. Primary coating materials used include polyvinyl chloride, bitumen, latex, plastisol,
silicone and other similar materials.
Geotextile applications include reinforcement for road construction.
Global Market
According to information provided by Dornier, the global geotextiles market is estimated to
have been worth $3 billion in 2009. The nonwovens sector accounts for 74.5 percent of the growth;
wovens, 25 percent; and other systems, 0.5 percent. The global growth of geosynthetics alone is
estimated at 5 percent annually.
According to GMA, the U.S. and Canadian geosynthetics market has a current estimated value of
$2.1 billion, with the U.S. share of that market put at 90 percent and the Canadian share at 10
percent. The sector employs some 12,000 people. Within that market, geotextiles has a 32-percent
share; geomembranes, 28 percent; geogrids, 14 percent; and drainage composites, 26 percent.
The nonwoven geosynthetics market has gone up and down in concert with the recent financial
market ups and downs. “Geosynthetic nonwovens volume dropped precipitously during 2008 and 2009,”
said Ian Butler, INDA’s director of market research and Statistics. “However, there has been
considerable growth in 2010.”
INDA estimates that in 2010, the North American nonwoven geotextiles industry had a
production volume of some 350 million square meters, with a roll goods value of nearly $300
million. “Most of these products are made from needlepunched PP, but there is some small volume of
of spunbonded PET used for asphalt overlay,” Butler said. “What has boosted the sales in 2010 was
the Obama administration’s plan to invest in the highway, airport and similar projects to provide
work and reinvest in the transportation infrastructure. In discussions with people in the industry,
they indicated that the low inventories of geosynthetics nonwovens at the end of 2009 led to many
very busy nonwoven needlepunch producers now catching up with demand.”
While
Textile World
Asia does not have access to specific data related to China’s geotextiles
market, that country has major infrastructure and erosion control projects planned, and the Chinese
market will account for the largest portion of new geosynthetics demand worldwide in the next few
years, according to information posted on the website of Cleveland-based industry research firm
Freedonia Group Inc.
Dornier reports the growing Indian geotextiles market has a value of some $49.6 million, but
it is expected to grow to nearly $66 million by 2012. Projected annual growth is 12 percent, and
long-term, it will increase to 20 percent, thanks to the further development of the country’s
infrastructure.
Fleissner, Dilo and Dornier expect much better results for 2010 than they realized in the
previous two years. This improvement is primarily thanks to structural adjustments, Dornier
reports, but the markets as such are in much better shape than previously. In spite of the falling
markets owing to the recent financial crisis, Fleissner reports constant demand for its machinery
and expects to report a successful 2010. Dilo also is seeing strong recovery since first-quarter
2010 and is working at full capacity, with delivery times up to seven months.
Dornier’s main markets are Germany, the Netherlands, Russia, China and India. Fleissner’s
markets include Germany and Russia as well, but also the United States. Dilo reports demand for
complete production lines for geotextiles is at the moment very high around the globe, but
particularly in Europe, the United States and Asia.
Important Sector
For each company, the geotextiles sector is an important market. Trützschler Nonwovens is
able to deliver lines for man-made fiber production as well as calenders or bonding machines such
as its Omega machine. The company reports lines already delivered for geotextile production have a
production capacity of more than 1,500 kilograms per hour and even at low fabric weights of 60 to
80 grams per square meter.
Dilo and Fleissner report there is an important upswing for nonwovens in general and
geotextiles in particular. The advantage of nonwovens as geotextile products is first of all their
high-volume and cost-effective production. A further criterion is their ability to stretch and
adapt to bumpy surfaces. Of outstanding importance is the finished product’s fabric width for
effective and economical road — or, increasingly, harbor — constructions. Dilo needlepunch machines
are constructed to allow a working width of 600 centimeters (cm).
On the other hand, geotextiles, which require high durability and strength, usually are made
of woven fabrics. Dornier reports its weaving machines are especially suitable for production of
open-mesh fabrics for armoring all kinds of constructions. Several layers of different
constructions can be combined. Woven fabrics also need to be produced in a wide width. In general,
machines with a nominal width of 540 cm and greater are used, while the hauling equipment for
street construction is usually designed to have a 500-cm width. A rapier weaving machine with
multiple weft insertion enables production of a defined product specific to the end-use.
The Future
The future for nonwoven and woven geotextiles is bright. However, for manufacturers to be
successful in this market segment, there must be a lot of know-how and communication efforts with
existing and potential customers. Comparing the difference between today’s customer and one of 10
years ago, one could note such comments as: “Our old customers are true professionals; our new
customers depend very much on our knowledge and experience.” This means knowing exactly the
markets, their requirements and possible civil engineering applications. Also, product requirements
and the number of innovations are continually increasing, which makes the markets highly
competitive and attractive, and creates more business.
Infrastructural programs are being undertaken mainly in emerging markets, but Europe and the
United States are seeing increased demand. Especially in emerging countries such as Brazil, India,
China and Russia, demand goes along with the rising mobilization and improved public transport
facilities — including new airports. The use of geotextiles significantly reduces civil engineering
construction costs and drastically extends the life of any road construction. “Textiles instead of
concrete” is not only a slogan, but a fact. Geotextiles have flexibility, making them better and
more economical than any other building materials.
April/May/June 2011